1. Field of the Invention
The present disclosure relates to a method and an apparatus for allocating or controlling transmission power when a User Equipment (UE) transmits uplink channels and signals. More particularly, the present disclosure relates to a method and an apparatus of multiplexing uplink channels or signals transmitted to the same base station (e.g., eNB) or to different base stations (e.g., eNBs), when the UE transmits various kinds of channels or signals through an uplink in a dual connectivity environment where signals are transmitted to or received from different base stations.
2. Description of the Prior Art
As communication systems have advanced, various types of wireless terminals have been introduced to consumers, such as companies and individuals. Current mobile communication systems have been affiliated with 3rd generation partnership projection (3GPP) technologies, for example, Long Term Evolution (LTE), LTE-Advanced (LTE-A), and the like. Such mobile communication systems are capable of transmitting and receiving a large amount of various type data (e.g., voice data, image data, and radio data) at a high speed. Accordingly, there is a demand for developing a technology for transmitting such a large amount of data as fast as a transmit rate in a wired communication network. In order to transmit such a massive amount of data, a plurality of cells may be used to transmit data.
Lately, there are many studies in progress for developing technology for utilizing small sized base stations (e.g., eNB) having relatively narrow service coverage such as a small cell in order to transmit a large amount of data at a high speed, and to stably transmit and receive data in an environment having a plurality of terminals densely located in a service area of a specific base station (e.g., eNB).
Further, there are also many studies in progress for dual connectivity that performing communication with a UE using a small cell and a typical macro cell. In such dual connectivity environment, the UE may perform wireless communication with multiple base stations (e.g., eNBs).
However, there has never been any discussion on how to distribute limited transmission power of a user equipment to a plurality of base stations in such a dual connectivity environment and what standard to be used to distribute transmission power to various type of simultaneously transmitted signals. Accordingly, there is a problem in that a UE processes high capacity data at a high speed using multiple base stations (e.g., eNBs). That is, a UE cannot transmit an uplink signal using dual connectivity without deciding how a UE distributes transmission power to each signal and what reference to be used for the UE to distribute the transmission power.